Titanium alloy for making a golf club head

ABSTRACT

A titanium alloy for making a gold club head includes aluminum in an amount ranging from 7.8 to 10.0 wt %, molybdenum in an amount of greater than 0 wt % and not more than 2 wt %, vanadium in an amount of greater than 0 wt % and not more than 2 wt %, silicon in an amount of greater than 0 wt % and not more than 2 wt %, and a balance of titanium, based on a total weight of the alloy.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a titanium alloy, more particularly to a titanium alloy for making a golf club head.

2. Description of the Related Art

Ti-6Al-4V titanium alloy is a conventional alloy for making a golf club head that is popular in the market because the golf club head made thereby has satisfactory mechanical strength and abrasive resistance meeting the requirements of most golf players.

Ti-6Al-1Mo-1V-2Zr titanium alloy is another conventional alloy for making a golf club head having superior mechanical strength and abrasive resistance. The alloy primarily includes 6 wt % aluminum (Al), 1.0 wt % molybdenum (Mo), 1.0 wt % vanadium (V), 2.0 wt % zirconium (Zr), and a balance of titanium (Ti). Although the aforesaid conventional titanium alloys can be used for making a golf club head having high mechanical strength and abrasive resistance, it is still desirable in the art to provide a titanium alloy usable to make a golf club head having relatively light weight at relatively low production cost while having superior mechanical strength and abrasive resistance.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a titanium alloy which can be used for making a golf club head having relatively low density, relatively low production cost, and superior mechanical strength and abrasive resistance.

Another object of the present invention is to provide a golf club head made of the titanium alloy.

Accordingly, in a first aspect of the present invention, a titanium alloy for making a golf club head includes:

aluminum in an amount ranging from 7.8 to 10.0 wt %;

molybdenum in an amount of greater than 0 wt % and not more than 2 wt %;

vanadium in an amount of greater than 0 wt % and not more than 2 wt %;

silicon in an amount of greater than 0 wt % and not more than 2 wt %; and

a balance of titanium, based on a total weight of the alloy.

In a second aspect of the present invention, a golf club head is made of the titanium alloy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As described above, the amount of aluminum in the titanium alloy of the present invention ranges from 7.8 wt % to 10 wt %, which is higher than that of aluminum used in the conventional Ti-6Al-4V and Ti-6Al-1Mo-1V-2Zr titanium alloys. An increase in aluminum reduces the density of the titanium alloy of the present invention. Therefore, a golf club head made of the titanium alloy of the present invention can have a relatively light weight compared to the golf club heads made of the aforesaid conventional titanium alloys. Preferably, the density of the titanium alloy of the present invention ranges from 4.2 g/cm³ to 4.3 g/cm³. Noted that the amount of aluminum in the titanium alloy of the present invention should not be higher than 10 wt %. If the amount of aluminum is higher than 10 wt %, the flowability of the alloy can be further reduced so that more silicon must be used to improve the flowability. As such, the amount of titanium in the titanium alloy must be significantly reduced, and the mechanical strength of the golf club head can therefore decrease. Furthermore, since the over growth of crystals in the alloy can be inhibited by aluminum, the crystal grains of the alloy can be maintained at a relatively fine size, which can improve the mechanical strength and abrasive resistance of the golf club head made of the alloy of the present invention.

Molybdenum in an amount of greater than 0 wt % and not more than 2 wt % can further increase the high temperature strength, the creep strength, and the high temperature hardness of the alloy so as to improve the abrasive resistance and the mechanical strength of the golf club head made of the alloy of the present invention.

Vanadium in an amount of greater than 0 wt % and not more than 2 wt % can also avoid the over growth of crystal grains in the alloy so as to micronize the crystal grains of the alloy, thereby improving the mechanical strength and abrasive resistance of the golf club head made of the alloy of the present invention.

The increased amount of aluminum in the alloy of the present invention reduces the flowability of the alloy during the fabrication of a golf club head from the alloy. Silicon is added to increase the flowability of the alloy and to improve the processability thereof. The processing of the alloy can therefore be made easier and the production cost can therefore be reduced.

The golf club head can be made of the alloy of the present invention using a conventional method for fabricating a golf club head that includes a former processing stage and a latter processing stage. The former processing stage involves precision casting technology, and generally includes the steps of mold-making, wax injection, hanging, dipping, dewaxing, casting, cutting, heat treating, etc. The latter processing stage includes the steps of surface grinding, washing, lacquering, punching, embedding, assembling, torque testing, polishing, etc.

EXAMPLE

An alloy was made using 8 parts by weight of aluminum, 1 part by weight of molybdenum, 1 part by weight of vanadium, 1 part by weight of silicon, and 89 parts by weight of titanium. A golf club head was fabricated from the alloy, and was compared to the golf club heads made of the Ti-6Al-4V titanium alloy and the Ti-6Al-1Mo-1V-2Zr titanium alloy in terms of tensile strength, yield strength, extensibility, and density. The results are shown in Table 1.

TABLE 1 Tensile Yield strength strength Extensibility Density (Mpa) (Mpa) (%) (g/cm³) Example 880 818 8 4.2–4.3 Ti—6Al—4V titanium 820 738 6 4.51 alloy Ti—6Al—1Mo—1V—2Zr 816 799 7.5 4.45 titanium alloy

As shown in the results of the aforesaid table, the tensile strength, the yield strength, and the extensibility of the golf club head made of the alloy of the present invention are improved, and the density thereof is reduced as compared to the golf club heads made of the Ti-6Al-4V titanium alloy and the Ti-6Al-1Mo-1V-2Zr titanium alloy. The applicants found that although the amount of aluminum is increased in the present invention, the mechanical properties of the titanium alloy of the present invention can be as high as or even higher than those of the aforesaid conventional titanium alloys. Therefore, the titanium alloy of the present invention can be used for making a golf club head having relatively light weight and superior mechanical strength and abrasive resistance.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A titanium alloy for making a golf club head, comprising: aluminum in an amount ranging from 7.8 to 10.0 wt %; molybdenum in an amount of greater than 0 wt % and not more than 2 wt %; vanadium in an amount of greater than 0 wt % and not more than 2 wt %; silicon in an amount of greater than 0 wt % and not more than 2 wt %; and a balance of titanium, based on a total weight of said alloy.
 2. The titanium alloy as claimed in claim 1, wherein said alloy has a density ranging from 4.2 to 4.3 g/cm³.
 3. The titanium alloy as claimed in claim 1, wherein said aluminum is in an amount of 8 wt %, said molybdenum is in an amount of 1 wt %, said vanadium is in an amount of 1 wt %, and said silicon is in an amount of 1 wt %, based on a total weight of said alloy.
 4. A golf club head made of the titanium alloy of claim
 1. 